Scissor-lifts and other worker lift devices are commonly used to lift workers and equipment during construction, painting, maintenance, assembly and manufacturing operations, including aircraft assembly. Scissor-lift devices typically include one or more sets of inter-tied scissors or a scissor stack operated by a hydraulic cylinder on a motor-driven base, and a basket from which a worker can work. Other lift devices such as boom lifts, cherry pickers and elevated work platforms have articulating or telescopic hydraulic, pneumatic, electrical or mechanical mechanisms carrying the worker basket and may be mounted on wheel-driven or track-mounted bases. When a lift device is being operated near fixtures or equipment, operator error or miscalculation can result in damage to the equipment or fixtures being worked on. Commonly a worker may be looking in one direction, and does not see how the lift device will contact surrounding equipment or fixtures as the lift is being moved because the portion of the lift outside of the view of the worker is the part that contacts the equipment or fixtures, sometimes resulting in damage. Alternately, the worker may not know, or may miscalculate, the orientation of the steering mechanism of the lift device. In such a case, when the worker moves a hand control to move the lift device laterally across the supporting surface, the device may move in an unexpected direction, contacting the equipment or fixtures being worked on. Lift devices that have overhangs can also be moved down into contact with fixtures or equipment.
Current lift devices typically rely on operator awareness and experience to avoid damaging contact with surrounding equipment and fixtures. Thus, there is an unmet need for a collision avoidance system and sensor modules easily adapted to lift devices and other components where collision or contact with surrounding objects is to be avoided.